The luxury yacht, Tanit, was captured by pirates off Somalia last weekend.
"Four hostages, including a child, were freed from the hijacked yacht after almost a week of captivity, Nicolas Sarkozy's office said.
The French military decided to move in when pirates refused their offers and increased threats against the hostages, it said.
A defense ministry source told CNN the pirates were threatening to execute their captives.
The four adults and a child had been held aboard their yacht, the Tanit, since it was seized in the Gulf of Aden on Saturday, the president's statement said.
There has been a series of high-profile and increasingly sophisticated pirate attacks in recent months."
LinkThe French? Just sayin'